1. Field of the Invention
This invention relates generally to protective caps and fastener covers, and more particularly to a fastener cover which is initially in the form of a deformable flat disk having an adhesive sealant on its bottom surface which is deformed over the head of a fastener with a tool that deforms the disk to completely encapsulate the head of the fastener and the radially surrounding surface to create an air-tight and liquid-tight seal and prevent loosening and relative movement therebetween.
2. Brief Description of the Prior Art
Headed fasteners such as bolts are commonly used in many outdoor installations where they are exposed to the harmful effects of the weather, such as fastening metal roofing and siding panels to the framework of building structures. If the head of the fastener is uncovered, thermal expansion and contraction due to exposure to temperature variations will often cause the fastener to become loose, and moisture can seep into the structure around the head of the loose fastener. Moisture can cause the fastener to rust or corrode and allows mildew to form around the fastener. Moisture also causes galvanic action between dissimilar metals which leads to corrosion.
The manual application of a caulking or sealing compound and the application of a poly-cloth around each individual fastener are common methods of sealing or protecting the heads of the fasteners. These methods are time consuming, unreliable, expensive, and unsightly. Also, prolonged exposure to extreme temperature variations, ultraviolet light, and moisture will often cause decay of the caulking or sealing compounds.
There are several patents which disclose various devices and methods for encasing the heads of fasteners.
Fletcher, U.S. Pat. No. 152,737 discloses a nut-lock which has a preformed hemispherical cup-shaped center with a radially extending circular flange indented with a series of radial cavities and a cut-away portion. The circular flange portion is compressed around the threaded portion of a bolt, above the nut to prevent the nut from being loosened.
Painaud, U.S. Pat. No. 3,704,647 discloses a preformed cap having a preformed cylindrical cavity at the center with a radially extending circular flange and a depending inwardly curved peripheral skirt at the bottom end. Upon striking the device, the inwardly curved skirt deforms inwardly underneath the head of the fastener in a space defined by a shoulder formed on the underside of the fastener head.
Gutshall, U.S. Pat. No. 3,885,492 discloses a preformed capped fastener formed of resilient flexible material which is mounted with a snap fit on the head of a fastener and has a yieldable central web on the top surface which gives way to permit a driver to be inserted into a drive recess on the head of the fastener.
Voller, U.S. Pat. No. 4,316,690 discloses a preformed capped bolt formed of rigid thermoplastic material which surrounds the head of the bolt and has an annular lip which cold flows to engage the threaded shank of the bolt when the nut is tightened on the bolt.
Johnston, Jr., U.S. Pat. No. 4,907,929 discloses a preformed dome-shaped bolt and nut cover formed of flexible resilient material which has an interior cavity with a lower portion which surrounds the nut and an upper portion which engages the threaded shank of the bolt extending out of the nut to prevent the cover from being removed.
Carlozzo et al, U.S. Pat. No. 4,923,348 discloses a preformed protective cap having a dome-shaped central portion surrounded by a flat annular flange. The cap is formed of a top layer of non-woven polyester fabric material, an underlying layer of a tacky unvulcanized butyl rubber compound, and a removable release liner of polyethylene film covering the bottom surface of the butyl rubber compound. The dome-shaped central portion is manually pressed about the bolt head.
Bell, U.S. Pat. No. 4,944,644 discloses a preformed screw fastener cap having a non-collapsible cylindrical upper portion which fits over the head of the fastener and a circumferential resilient clip or catch an the lower end which snap fits over a metal washer beneath the head of the fastener and compresses a rubber washer beneath the metal washer.
Henry, U.S. Pat. No. 4,826,380 discloses a pre-cast dome-shaped protective cover for cap screws having a dome-shaped outer shell filled with a curable sealant which is pressed over the exposed end of a fastener.
Coleman, U.S. Pat. No. 5,129,770 discloses a preformed dome-shaped protective cover for cap screws having a central cavity with an annular compression ring and annular gripping rings on the interior of the cavity which engage the head of the fastener. The cover is pressed onto the head of the fastener with a tool having a concave recess which mates with the hemispherical exterior of the cover.
Simpson et al, U.S. Pat. Nos. 4,936,938, 5,096,759, and 5,142,837 discloses laminated sheets of roofing material and process for manufacturing the sheets in rolls. The laminated sheets have a top layer of aluminum foil adhesively bonded to a polyethylene layer, an underlying layer asphalt, and a release paper covering the bottom surface of the asphalt. The roofing material sheets are applied over a roofing surface as a series of elongate overlapping parallel strips.
Best, U.S. Pat. No. 5,419,666 discloses a two-piece protective waterproof cover assembly which includes a rigid dome-shaped cover which overlies the head of the fastener and provides a cavity around the head to permit loosening of the fastener and movement of the head away from the surface on which is is initially installed. A circular flexible pad having an adhesive on its bottom surface overlies the dome-shaped cover and adheres it to the support structure.
The present invention is distinguished over the prior art in general, and these patents in particular by a pliable flat disk of laminated construction having a thin top layer of deformable material bonded to a relatively thicker intermediate layer of pliable adhesive sealant material and a removable bottom layer of release paper covering the exposed surface of the sealant material. The flat disk is deformed during installation to cover and seal the head of a fastener protruding from a surface. The disk is installed and deformed by a tool having an end with a recess slightly deeper than the height of the head of the fastener and an interior slightly larger than the outer periphery of the head of the fastener. The release paper is removed to expose the adhesive sealant material and the flat disk is generally centered and placed, adhesive side down, onto the fastener head. The tool is then centered above the disk and fastener head and pressed downwardly with a twisting motion to deform the flat disk to encompass and conform substantially to the shape of the head of the fastener and cover a surface radially surrounding the fastener head such that the deformed disk is adhered to the fastener head and to the radially surrounding surface to provide an air-tight and liquid-tight seal between the fastener head and the radially surrounding surface and to prevent relative movement therebetween. It will also cover and seal a washer if one is used with the fastener.